Celebrity Twitter users were last night bracing themselves for a barrage of lawsuits from Lord McAlpine after he was wrongly accused on the social network site of being a child molester.

The Tory grandee is expected to sue at least 10,000 people over the malicious claims that appeared in the wake of a BBC Newsnight investigation into a paedophile ring at care homes in North Wales.

And he could hit high-profile tweeters such as Speaker’s wife Sally Bercow and comedian Alan Davies who both mentioned the peer on their accounts. The sensational move could involve the largest number of defendants in British legal history.

Mention: Sally Bercow (Photo: Twitter)

Former Tory Party treasurer Lord McAlpine has hired a team of experts who have collated a “very long list” of people and their offending messages, even those that have been deleted. More than 1,000 original tweets and 9,000 retweets have already been identified.

His solicitor Andrew Reid said: “We have been watching people who have been taking down what they put on Twitter.

“We already have all the information. We have found a couple of firms of experts who have produced pretweets, post-tweets, the effect of the tweets and the retweets.

"What starts at one ends up as 100,000 in some cases.

“Twitter is not just a closed coffee shop among friends. It goes out to hundreds of thousands of people and you must take responsibility for it. It is not a place where you can gossip and say things with impunity, and we are about to demonstrate that.”

Around 40 people have approached Lord McAlpine’s legal team to apologise and have paid a nominal fee in damages, believed to be £5.

Lawyers are thought to want the small amount for most of the cases with the cash going to a children’s charity.

Twitter became the hub of fevered ­speculation before the Newsnight programme was screened.

Long list: Alan Davies could be in trouble (Photo: Getty)

Reporter Iain Overton sparked the frenzy by tweeting a senior Tory would be exposed as a paedophile that night.

The programme did not name Lord McAlpine. It later emerged that he was the victim of mistaken identity and innocent of the claims. He said the episode left him “shattered”.

QI star Davies asked his 440,000 followers on November 3 “Any clues as to who this Tory paedophile is.... ?” before retweeting a response naming Lord McAlpine.

John Bercow’s wife apologised for her part in falsely ­identifying the peer as a paedophile but said her actions were not libellous.